using System;

namespace ET
{
    /// <summary>
    /// 时间工具类
    /// </summary>
    public static class DateTimeUtil
    {
        /// <summary>
        /// 时间戳计时开始时间
        /// </summary>
        private static DateTime timeStampStartTime = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

        /// <summary>
        /// DateTime转换为10位时间戳（单位：秒）
        /// </summary>
        /// <param name="dateTime"> DateTime</param>
        /// <returns>10位时间戳（单位：秒）</returns>
        public static long DateTimeToTimeStamp(DateTime dateTime)
        {
            return (long)(dateTime.ToUniversalTime() - timeStampStartTime).TotalSeconds;
        }

        /// <summary>
        /// DateTime转换为13位时间戳（单位：毫秒）
        /// </summary>
        /// <param name="dateTime"> DateTime</param>
        /// <returns>13位时间戳（单位：毫秒）</returns>
        public static long DateTimeToLongTimeStamp(DateTime dateTime)
        {
            return (long)(dateTime.ToUniversalTime() - timeStampStartTime).TotalMilliseconds;
        }

        /// <summary>
        /// 10位时间戳（单位：秒）转换为DateTime
        /// </summary>
        /// <param name="timeStamp">10位时间戳（单位：秒）</param>
        /// <returns>DateTime</returns>
        public static DateTime TimeStampToDateTime(long timeStamp)
        {
            return timeStampStartTime.AddSeconds(timeStamp).ToLocalTime();
        }

        /// <summary>
        /// 13位时间戳（单位：毫秒）转换为DateTime
        /// </summary>
        /// <param name="longTimeStamp">13位时间戳（单位：毫秒）</param>
        /// <returns>DateTime</returns>
        public static DateTime LongTimeStampToDateTime(long longTimeStamp)
        {
            return timeStampStartTime.AddMilliseconds(longTimeStamp).ToLocalTime();
        }

        public const string FormatA = "yyyyMMdd";
        public const string FormatB = "yyyyMMddHH";
        public const string FormatC = "yyyyMMddHHmm";
        public const string FormatD = "yyyyMMddHHmmss";
        public const string FormatE = "yyyyMMddHHmmssFFF";
        public const string FormatF = "HHmmss";

        /// <summary>
        /// 当前时间 yyyyMMddHHmmssFFF
        /// </summary>
        /// <returns></returns>
        public static long GetNowTime(string format)
        {
            if (format == FormatE)
            {
                return UpTimeStamp(long.Parse(TimeHelper.DateTimeNow().ToString(format)));
            }
            else
            {
                return long.Parse(TimeHelper.DateTimeNow().ToString(format));
            }
        }

        public static long UpTimeStamp(long lg)
        {
            if (lg == 0) return lg;
            string logStr = lg.ToString();
            if (logStr.Length < 17)
            {
                return UpTimeStamp(lg * 10);
            }
            else
            {
                return lg;
            }
        }

        /// <summary>
        /// 当前时间 yyyyMMddHHmmssFFF
        /// </summary>
        /// <returns></returns>
        public static long GetTime(DateTime dt, string format)
        {
            if (format == FormatE)
            {
                long lgTime = UpTimeStamp(long.Parse(dt.ToString(format)));
                return lgTime;
            }
            else
            {
                return long.Parse(dt.ToString(format));
            }
        }

        /// <summary>
        ///  获取指定中国毫秒级时间戳所在日期的凌晨5点的时间戳
        /// </summary>
        /// <param name="timestamp">13位时间戳</param>
        /// <returns></returns>
        public static long GetChinaToday5AMTimestamp(long timestamp)
        {
            DateTime dateTime = DateTimeUtil.LongTimeStampToDateTime(timestamp);
            // 转换为 DateTimeOffset
            DateTimeOffset dateTimeOffset = new DateTimeOffset(dateTime);

            // 获取当天日期的凌晨00点
            DateTimeOffset today = new DateTimeOffset(dateTimeOffset.Year, dateTimeOffset.Month, dateTimeOffset.Day, 0,
                0, 0, TimeSpan.FromHours(8));

            // 设置凌晨5点的时间
            DateTimeOffset today5AM = today.AddHours(5);

            // 返回凌晨5点的时间戳（毫秒级）
            return today5AM.ToUnixTimeMilliseconds();
        }
    }
}